Shell mold making machines



Sept. 3, 1957 T. K. HUTcHlNsoN ETAL 2,804,661

SHELL MOLD MAKING MACHINES Filed Aug. s1, 195s 4 sheets-sheet 1 THOMAS- K.HurcmNsoN O.C. KEMP HU'rcHlNsoN Sept 3, l957 T. K. HurcHlNsoN ET AL 2,804661 SHELL MOLD MAKING MACHINES Filed Aug. 31., 1953 4 Sheets-Sheet 2 FIG. 7.

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' lmllmglgmglgx /35 INVENTORS L i? THoMAs K. HuTcHlNsoN O. C. KEMP lHxJTcl-llwsscm Sept. 3, 1957 T. K. HUTcHlNsoN ET AL 2,804,651

SHELL. MOLD MAKING MACHINES 4 Sheets-Sheet 3 F IG. I I

Filed Aug. s1, 195s 74 l2 FIG. IO.

A .INVENToRs THOMAS KHUTcHlNsoN 0.C. KEMP HuTcHINsoN Sept. 3, 1957 Filed Aug. 31,v 1955 T. K. Hu'rcHlNsoN ET AL 2,804,661

SHELL MOLD MAKING MACHINES 4 Sheets-Sheet 4 INVENToRs THoMAs 'K.Hu1'cHuNsoN O. C. KEMP Hu'rcHlNsoN E @ym 2,804,661 SHELL Mom MAKING MACHINES Thomas K. Hutchinson and Oliver C. Kemp Hutchinson, Alton, lll.

Application August 31, 1953, Serial No. 377,419

i4 Claims. (Cl. 22-9) This invention relates to improvements in molding machines. More particularly this invention relates to improvements in molding machines that can form shell molds.

It is therefore an object of the present invention to provide an improved molding machine for making shell molds.

In the casting of metals, it is frequently the practice to form a mold of sand by placing sand in contact with a pattern. In some instances the pattern is heated and the sand which is placed in contact with it has a binder in it and the binder responds to heat from the pattern to form a thin shell of sand and binder in contact with the pattern. Such a shell has become known in the casting art as a shell mold. These shell molds have a great deal of strength and are able to follow the shape of the pattern with greater accuracy and completeness than othertypes of molds. Accordingly, shell molds have been found to be very desirable, and a number of machines for making shell molds are coming into use.

-In the making of shell molds, the admixed sand and binder is placed on top of the heated pattern and left there for a predetermined period of time. The longer the admixed sand and binder is left in contact with the heated pattern, the thicker the shell mold will be, because the increased time will enable the heat from the pattern to heat more of the binder. At the conclusion of the predetermined time, the excess binder and sand must be removed and the shell mold given an additional time to curef The admixed sand and binder should be confined to keep it from becoming lost and to keep it from entering the moving parts of machinery nearby. The present invention provides a molding machine which confines the admixed sand and binder and keeps that admixed sand and binder out of the moving parts of the machine, but which selectively places that admixed sand and binder in engagement with a heated pattern.

The present invention mounts the heated pattern on a pattern-carrying support which is pivoted for rotation, and it also provides a container for the admiXed sand and binder which can be placed in engagement with the pattern on the pattern-carrying support and then the pattern and the container inverted to place the sand in engagement with the pattern. The container and pattern will remain inverted for a predetermined period of time so that the admixed sand and binder can be heated to the desired depth by the heat from the pattern, and thereafter the container and the pattern-carrying support will be moved apart and the shell mold on the pattern permitted to cure The container and the pattern are placed in engagement with each other at a time when the container has its open end up; and prior to the time the container is inverted, the pattern has completely closed the open end of that container. In this way, the sand and binder are completely confined and are kept from being lost or getting into the moving parts of the molding machine. It is therefore an object of the present invention to pro- 2,8%,661 Patented Sept. 3, 1957 vide a molding machine with a rotatable pattern-carrying support and a container which can be placed in register with a pattern on that support and then inverted to place sand and binder in engagement with the pattern.

The molding machine provided by the present invention secures one side of the container to the rotatable patterncarrying support and supports the other side of the container on a track. This track guides the one side of the container as the other side of the container is moved by the support, and the container is thus moved along with the open end thereof substantially up until the pattern on the pattern-carrying support has been placed in engagement with that open end. Thereafter, the track holds the pattern and container together so that the admixed sand and binder cannot escape. Once the shell mold has been formed, the track will then guide the container in lits movement away from the pattern-carrying support to its initial position. It is therefore an object of the present invention to provide a molding machine with a track that guides the container for the adrnixed sand and binder. The pattern-carrying support provided by the present invention and the container provided by the present invention will be moved by a motor. The initial and final positions of the pattern-carrying support and the container are readily controlled by limit switches adjacent a follower which is driven by the motor. The follower is actually driven by a worm shaft which is geared to the motor. One of the switches will stop movement of the motor in the forward direction when the desired position of the pattern-carrying support and of the container is reached, and the other of the switches will stop movement of the motor in the reverse direction when the de sired position of the pattern-carrying support and container are reached. These switches are mounted on adjustable supports so that the initial and final positions of the pattern-carrying support and the container can be adjusted as desired. It is therefore an object of the present invention to provide limit switches that are mounted on adjustable supports to control the initial and final positions of the pattern-carrying support and container of a molding machine.

The patterns used in making shell molds must be kept in a heated condition, and the patterns used with the molding machine of the present invention are therefore heated. These patterns will have electric heating elements embedded within them and the leads from those heating elements must be connected to a suitable source of electric current. However, since the pattern is alternately inverted and then restored to its original position, there would be the problem of the leads from the heating elements becoming twisted and becoming fatigued. The present invention obviates this problem by providing a plurality of flexible conductors which are of spiral configuration and which are connected to the stationary and rotating parts of the machine. The leads from the electric heating elements can be connected to the inner ends of those exible conductors and the source of electric current can be connected to the outer ends of those iiexible conductors and the conductors will transmit the current while absorbing the relative rotation between the stationary and movable parts of the molding machine. It is therefore an object of the present invention to provide a molding machine with flexible conductors of spiral configuration that transmit the current to the heating elements of the pattern.

Other and further objects and advantages of the present invention should become apparent from an examination of the drawing and accompanying description.

In the drawing and accompanying description a preferred embodiment of the present invention is shown and described but it is to be understood that the drawing and accompanying. description are for the purpose of illustration only and do not limit the invention and that the invention will be defined by the appended claims.

In the drawing:

Fig. 1 is aside elevational view of one form of moldingmachine that is made in accordance with the principles and teachings of the 'present invention,

, Fig. 2 is an end elevational view of the molding machine of Fig. 1,

Fig. 3 is an enlarged plan view in section of a portion of the molding machine of Figs. Vl and 2, and it is taken along the plane indicated by theline 3 3 in Fig. l,

. Fig. 4 vis an enlarged elevational view in section of a portion of the molding machine of Figs.u 1 and 2, and it is taken along the plane indicated by the line 4 4 in Fig. 1,

Fig, Y5 Vis an enlarged plan View in section of` another portion of the molding machine of Figs. 1 and 2, and it is taken along the plane indicated by the line 5 5 of Fig. 1, Y

Fig. 6 is an elevational view in section of the portion o f the molding machineshown in Fig. 5, and it is taken along the broken plane 6 6 in Fig. 5, Y

y Fig. 7 is an enlarged View of another portion of the molding machines of Figs. l and 2, and it is taken along the plane indicated by the line 7 7 in Fig. 2 but it shows the parts in the final rather than the initial position,

- Fig. 8 is a plan view of the pattern-carrying support of the molding machine of Figs. l and 2, and it is taken along the plane 8 8 of Fig. 7,

Fig. 9 is an enlarged view of another section of the r'nc'alding machine of Figs. 1 and 2, and it is taken along the plane 9 9 in Fig. 7, n a Fig. l0 is an elevational View of another section of the molding machine of Figs. l and 2, and it is taken along the plane indicated by the line 10 10 in Fig. 7,

Fig. 1l is an enlarged view of another section of the molding machine of Figs. l and 2, and it istaken along the plane indicated by the line 11 11 in Fig. 4 but it shows the elements afterv they have been rotated ninety degrees from the position of Fig. 4,

Fig. 12 is a cross sectional end view of the portion of the molding machine shown in Fig. l1, and it is taken along the plane indicated by the line 12-12 in Fig. l1,

Fig. 13 is a schematic view of the pattern-carrying support and the container of the molding machine of Figs. l and 2, and it shows that support and container i'n the initial position,

Fig. 14 is a schematic diagram of the support and container of Fig. 13, and it shows those elements inthe position they assume after the support has rotated ninety degrees,

Fig. 15 is a schematic diagram of the support Vand container of Figs. 13 and 14 and it shows those elements 'afterthe support has rotated one hundred and eighty degrees, Y

16 is a schematic diagram of the support and container of Figs. 13-15, and it shows those elements after the support has rotated forward two hundred and thirty degrees, and n Fig. 17 is a schematic diagram of the support and container of Figs. 13-16, and it shows those elements after the support has rotated three hundred and sixtydegrees.

Referring to the drawing in detail, the numeralsl() and 21 denote the side plates of a molding machine that is made in accordance with the principles and teachings of the present invention. These side plates are maintained in fixedly spaced relation by tie. bars 22 ,which extend between and are rigidly secured to the side plates and 21. An opening is formed adjacent the lower edge of the side plate 20 and a mounting platform 24 is 'formed on that side plate adjacent that opening. This mounting platform can readily be formed by welding.

A generally cylindrical bearing and gear housing 26 is bolted to the side plate 20 by bolts 28 and nuts This housing has a generally rectangular section extending from the right hand side thereof, as that housing is viewed in Fig. 1. A generally cylindrical interiorly flanged portion of the housing 26 extends rearwardly and is snugly mounted in a mating opening in the side plate 20. This generally cylindrical internally flanged portion of the housing 2t) receives and holds an anti-friction bearing 32. The outer race of the bearing 32 will fit tightly within the cylindrical interiorly flanged portion of the housing 26, and the inner race of that bearing will snugly llt a hollow pivot or shaft 34. The pivot 34 has a radially extending flange which tits within the interiorly directed flange of the housing Z6, and it is also provided with an outwardly projecting flange 36 at the inner end thereof. The other end of the pivot 34 is of reduced cross section.

An axially extending duct 38 is formed in the wall of the hollow pivot 34 and a pipe fitting 40 is connected to one end of that duct, as best shown in Fig. ll. The other end of the duct 38 opens to the exterior surface of the shaft 34 in register with a sealing sleeve 60. This sleeve has a series of three annular recesses 62, 64 and 66. The recess 64 is directly in register with the one end of the duct 38 and directly communicates with it. The recesses 62 and 66 are oppositely disposed of the recess 64, and each of those recesses has an O-ring 68 in it. The O-rings will bear against the recesses 62 and 66 and also bear against the shaft 34, thus providingv a seal while yet permitting relative rotation betweenI the pivot 34 and the sealing sleeve 60. A pipe fitting 44 is connected to the sealing sleeve 60 and will communicate with the annular recess 64. A pipe 46 is connected 'toI the sealing sleeve 60 by the pipe fitting 44. Compressed air or other fluid under pressure can be introduced into the pipe 46 and thus directed to the pipe 42 which is connected to the pipe fitting 40.

A worm wheel 48 is mounted on the shaft 34 and is maintained in fixed relation relative to that shaft by a key 50. The worm wheel 48 is disposed within the bearing and gear housing 26. A cover 52 is provided for 'the front of the bearing and gear housing 26 and bolts 54 extend through openings in that cover to seat in the housing and releasably secure the cover to that housing. A bulge 5 6 is provided in the cover 52 adjacent the right hand side of that cover. The cover 52 also has an axially directed flange 58 thereon and that flange extends into lthe sealing sleeve 60. A set screw 70 extends through a threaded opening in the sleeve 60 and bears against the flange 58 on the cover 52. The cover 52 is stationary since it is bolted to the gear housing 26 and since the gear housing 26 is bolted to the side plate 20. Accordingly, the set screw 70 will maintain the sealing sleeve A60 stationary. l Y

A sleeve 72 telescopes over the reduced diameter lend of the pivot or shaft 34, and it is rigidly secured to that shaft by two set screws 74 that extend through threaded openings in the sleeve 72 and seat against the shaft 34. A small amount 'of tolerance will be provided between the left hand end of the sealing Vsleeve 60 'and the right hand end of the sleeve 72, because the sleeve 60 will be stationary while the sleeve 72 will rotate with the shaft 34.Y A sleeve of insulation, such as fibre or the like, I76 is snugly telescoped over the sleeve 72. A number of openings 78 are provided in the sleeve 76 and in the sleeve 72, and those openings are in register with each other. A number of washers A80 of insulation, such as fibre or the like, are pressed'onto the sleeve 76 of insulation. The washers 80 are spaced apart by rings 82 of metal which snugly fit the sleeve of insulation 76. One washer 80 bears against theshoulder 73 adjacentthe :right hand end, of the sleeve 72, as that sleeve 'is viewed in Fig. 1l. A metal ring 82 bears against that first washer 80 and in turn has a washer 80 in engagement' with its other face. The rings 82 and the washers 80 alternate throughout the length of the sleeve 76 whichis snugly fitted on the sleeve 72. The Washers 80 andthe rings 82 will' rotate with the sleeve 76 and with the sleeve 72 as a unit. The rings 82 will have openings of reduced diameter through them, and those openings will be in register with the openings 78 in the sleeves 72 and 76. A washer 84, preferably of metal, will be disposed outwardly of the outermost washer 80 and that washer will have a small tolerance with the recess 75 at the left hand end of the sleeve 72. The washer 85 will t within a sleeve 87 of insulation, such as fibre or the like, and it will be txedly secured to that sleeve by screws 86. The sleeve 87 will be concentric and coaxial with the pivot or shaft 34 and with the sleeves 72 and 76 which are rotatable with that shaft. A working tolerance will be provided between the outer peripheries of the washers 80 and the inner periphery of the sleeve 87.

A number of conductors 88 of a flexible material, such as phosphor bronze or the like, are disposed between the washers 80. The inner ends of the conductors 88 are secured to the rings 82, and the outer ends of those conductors are secured to bolts 90 which are equipped with nuts 92. The bolts 90 extend through the sleeve 87 of'insulation, and they secure the outer ends of the conductors 88 to that sleeve. Hence the outer ends of the conductors 88 will be held stationary. Suitable leads 94 are connected to the bolts 90 by the nuts 92, and those leads can be connected to a suitable source of electric current. The inner ends of the conductors 88 will move with the rings 82 and thus the conductors 88 will have their outer ends stationary and their inner ends movable. The spiral configuration of the conductors 88 permits this stationary holding of the outer ends thereof and the moving of the inner ends thereof because those conductors will make a successively tighter and looser spiral to accommodate the rotation of the sleeves 72 and 76 relative to the sleeve 87. A number of leads 96 are connected to the metal rings 82 and thus to the inner ends of the flexible conductors 88. The conductors 96 are encased within a sheath of insulation 97 and that sheath of insulation extends through the axially extending opening in the center of the shaft 34 to the inner end of that shaft. The sheath of insulation 97 is cut away adjacent the left hand end of the shaft 34 to permit the individual conductors 96 to extend to the particular opening 78 for which they are intended. The sleeves 72 and76 are xedly secured to the metal rings 82 by pins 98 which extend through each of those elements. These pins are preferably of insulation. A generally U-shaped bracket 100 is secured to the washer 84 by screws 102 and is secured to the cover 52 of the gear housing 26 by other screws. This bracket holds the sleeve 87 stationary relative to the rotating sleeve 72, and also maintains the sleeve 87 centered relative to the sleeve 72.

The numeral 104 generally denotes a pattern-carrying support for the molding machine provided by the present invention. That support is shown as being formed of four flanged plates welded at the corners. Two angles 166 are Welded to the bottom edges of the flanged plates of the support 104 and the plates and the angles form a rigid and sturdy support. The flange 36 of the pivot 34 is secured to one of the flanged plates of the support 104, and that flanged plate has an opening therethrough which receives a cylindrical projection on the flange 36. Thus the shaft 34 supports one side of the pattern-carrying support 104. The other side of the pattern-carrying support is held by the pivot or shaft 106. The shaft 106 has a flange 108, and that ange is fxedly secured to another flanged plate of the support 104. A bearing housing 110 is mounted in an opening in the side plate 21, and it is secured to the side plate by screws 111. The bearing housing 110 receives and holds the outer race of an antifriction bearing 112, and the inner race of that bearing snugly receives the outer end of the shaft 106. A cover 114 is -provided for the bearing housing 110, and screws 116 extend through openings in the cover 114 and seat in' the bearing housing 110.

Two arms are secured to the pattern-carrying supp-ort 104, and those arms extend to the right of that support,- as that support is viewed in Fig. 7. A shaft 120 is secured to and held by the arms 118. A sleeve 124 is telescoped over the shaft 120 before that shaft is secured to the arms 118, and arms 122 are secured to the sleeve 124 before that sleeve is telescoped over the shaft 120. The sleeve 124 is rigidly secured to the arms 122 and holds those arms in rigidly spaced relation. Washers 126 are telescoped over the shaft 120 and they are disposed between the arms 122 and 118. A suitable working clearance will be provided between the arms 118 and the washers 126 and between the washers 126 and the arms 122. Washers 128 will be disposed adjacent the outer faces of the arms 118, and those washers will be held in assembled relation with shaft 120 by bolts 130 which seat in the ends of that shaft.

A sleeve 132 extends between the free ends of the arms 122. This sleeve will be rigidly secured to those arms, as by welding. The sleeve 132 rotatably receives a shaft 134, and that shaft has grooved wheels 136 thereon. The grooved wheels serve as followers for a track 138, and that track is rigidly mounted on the side plates 20 and 21.y The track has a semicircular section adjacent the left hand end thereof, as that track is viewed in Fig. l, and it has a straight tangentially extending section at its right hand end, as that track is viewed in Fig. l. The right hand end of the track 138 is at a level approximating the level of the pivots 106 and 34, but the left hand end extends well above the level of those pivots. The track 138 is spaced from the side plates 20 and 21 by spacing sleeves 142, and the Vtrack is rigidly secured to those side plates by bolts 140, as shown particularly in Fig. 9. The track 138 has a tapered surface which receives the grooved wheels and will conine those wheels to the desired path.

A pair of angle irons 144 extend between and are welded to the spaced arms 122. These angle irons coact l with the arms 122 and the sleeves 124 and 132 to form a rigid and sturdy support. The angle irons 144 have openings therethrough and those openings receive the bolts 146 and those bolts have nuts 148 on the threaded ends thereof. The bolts extend through openings in angle irons 152 which are mounted on opposite walls of a container 154 forvadmixed sand and binder. The nuts 148 will be removed to permit the insertion of the bolts 146 through the openings in the angle irons 152, and helical springs 150 will be telescoped over the bolts 146 before the threaded ends thereof are passed through the openings in the angle irons 152. The angle irons 144 and 152, and the bolts 146 and the nuts 148, and the helical springs 150 provide a lost motion connection between the arms 122 and the container 154. This lost motion connection permits limited relative movement of the container 154 relative to the arms 122 but prevents unlimited movement of that container relative to those arms.

A number of angles 156 are secured to the container 154 at the open end of that container, and those angles support a framework 158 of wood. Bolts and nuts 157 extend through aligned openings in the angles 156 and in the wooden frame 158 to secure that frame to those angles. A gasket 160 of heat resilient flexible material is suitably secured to the. frame 158. Heat resistant synthetic rubber Vis very useful for this purpose.

A pattern 162 is secured to the pattern-carrying support 104 by bolts 164 which extend through projections on the pattern and seat in the flange of the support 104. This pattern will have electric heating elements of standard design and make, embedded within it; and the pattern will be made of metal so it will readily conduct and radiate heat. The electric heating elements of the pattern 162 will extend outwardly from that pattern, and they are denoted by the numeral 178, as shown particularly in noteer Fig. 7; In one embodiment of the invention it has been found desirable to use electric heating units that operate on 'twohundred andl twenty volts, and the leads 178 are suitably insulated for safe use with that voltage.

VA cylinder 168 is secured to the cross angles 166 on the pattern-carrying support, and that cylinder has a piston 170 reciprocable therewithin. The piston 170 carries a Vspider'171 on the outer end thereof and that spider carries two ejecting pins 172. The pins 172 are surrounded by helical springs 173 that bear against the bottom of the pattern 162. These springs normally hold the ejecting pins 172 in the position shown in Fig. 7, but whenever uid is introduced into the cylinder 168 under pressure, those pins will move upwardly through openings in 'the pattern 162 and eject the vshell mold from that pattern. A solenoid, not shown, will be connected between the ends of the pipe 42 and that solenoid will control the ilow of fluid to the cylinder 168.

A vibrator 174 is mounted on the pattern-carrying support 104 and that vibrator will assist the admixed sand and binder in intimately contacting all parts of the exposed surface of the pattern. The vibrator will be energized during the first moments when the sand and binder are engaging the exposed surface of the pattern. Leads 176 extend from the vibrator 174.

As indicated particularly in Fig. ll, live flexible conductors 88 are provided, and live leads 96 are provided. Two of those leads will extend to the leads 178 of the heating elements for the pattern 162. Another of the leadsr96 will extend to one of the leads 176 of the vibrator 174, still another of the leads 96 will extend to one of Ithe leads of the solenoid valve, not shown, and the remaining lead will be connected to the remaining lead of the vibrator 174 and to the remaining lead of the solenoid valve, notshown. yThus the last lead 96 will be a common lead for the vibrator 174 and for the solenoid valve, not shown. Y

n A motor, 190 is mounted on the platform 24 which is supported by the side plate of the molding machine. Thershaft of the motor 190 extends into a exible coupling 188, and a vertically directed shaft 184 extends upwardly from the exible coupling 188. The upper end of 'theshaft 184 has worm threads 182 cut in it, and the upper end of that shaft extends into ,the gear housing 26, as shown particularly in Fig. 3. The worm threads 182 on the shaft 184 engage and drive the worm wheel 48 in the housing 26. As explained above, the worm wheel 48 is keyed 'to the 'shaft 34, and thus rotation of the shaft '1 84 will cause rotation of the pattern-carrying support 104.

lT he upper end of the shaft l184 is hollow and a reduced diameter portion of a shaft 185 extends into the hollow upper end of the 'shaft 184. A pin 186 extends through the upper end of the shaft 1`84 and through the reduced diameter section of the shaft 185 to lock those shafts for concurrent rotation. ATheshaft 185 extends out of the top of the gear housing 26 and into the bottom of a switch housing 192 secured to the side plate 20 by bolts and nuts. A bearing 194 is provided in the top of the switch housing 192, and that bearing holds the upper end of the shaft 185, as shown particularly in Fig. 6. The upper end of the shaft 185 has worm threads on it, and these threads move a follower 196. The follower 196 has a narrow n extending along one edge thereof, and that fin is held -and guided by spaced guides 198. Follower 196 will move up and down as the direction of rotation of the shaft` 185 is reversed; the guides 198 holding the follower 196 against rotation.

A threadedv rod 200 extends through the upper wall of the switch housing'192 and has the bottom thereof journaled in a 'bearing'206l The upper end thereof is held by a collar which seats in threads in that upper wall. A secondthrea'ded rod 202 Ais disposed in the switch housing 192, and it V'has `the lower end thereof disposed in a sleeve 206 and has its upper end held in` a sleeve 204 seated in the upper wall of th housing 192. A supporting block 208 for a switch is threaded onto the rod 200 and has a second opening which telescopesfreely over the threaded rod 202. This block 208 supports the switch 210. Rotation of the threaded rod 202`will cause the block 208 to move up and down in the switch housing 192; the block 208 freely sliding along the threaded rod 202. A supporting block 212 is threaded onto the rod 202 and has an opening which telescopes freely over the threaded rod 200. The block 212 supports the switch 214. Rotation of the threaded rod 202 will adjust the vertical position of the block 212; the block 212 telescoping freely along the threaded rod 200. Actuators 216and 218 are provided for the switches 210 and 214 respectively, and the rollers of those actuators will be engaged and moved by the follower 196. The switches 210 and 212 are limit switches and the switch 210 will limit the rotation of the motor 190 which forces the fol lower 196 to move upwardly; and the switch 214 will limit rotation of the motor 190 which causes the follower 196 to move downwardly. The setting of the switches 210 and 214 is adjusted by rotation of the threaded rods 202 and 200, and those switches will be set so the initial and nal positions of the pattern-carrying support and the container are as desired.

The initial position of the parts of the molding machine provided by the present invention is shown in Figs. 1, 2 and 13. In that initial position the patterncarrying support holds the pattern 162 up, the open end of the container 154 is up, and the ejecting pins 172 have their upper ends flush with the upper surface of the pattern 162. The vibrator 174 is de-energized, as is the solenoid, not shown, which controls the flow of fluid through the pipe 42. However, the heating elements are energized and the pattern 162 is hot. An adequate supply of admixed sand and binder, which can be a phenolic resin, is in the bottom of the container 154. The follower 196, in the switch housing 192, will be in engagement with the actuator 218 of switch 214. When the operator desires to initiate a cycle of the molding machine, he presses a starting switch, not shown, which energizes the motor 190. Energization of the motor 190 will rotate the shaft 184, and this will cause rotation of the shafts 34 and 106 as well as rotation of the shaft 18S. The rotation of the shaft 185 will start the follower 196 upwardly toward the actuator 216, and the rotation of the shafts 34 and 106 will start the pattern-carrying support 104 rotating in a clockwise direction and will cause the container 154 to start moving to t'he left, as the support 104 and the container 154 are viewed in Figs. l and l3. As the pattern-carrying support 104 rotates, the shaft 120 and the arms 118 and 122 will pull the left hand side of the container 154 downwardly so the top of the container 154 will not be horizontal. However, the angle which the top of the container 154 makes with the horizontal is then ra-ther small, as indicated particularly by Fig. 14; and there-v fore the admixed sand and binder in the bottom of the container will not tend to fall out of the container. Con- -tinued rotation of the shaft 184 will cause the support 104 to rotate to the position shown in Fig. 16, and the container 154 will move to the position shown in Fig. l5. It will be noted that the left hand side of the container is now above the level of the right hand side of that container, but once again the angle which the top of the container 154 makes with the horizontal is a very small angle. Consequently, the admixed sand and binder cannot fall out of the container 154. Still further rotation of the shaft 184 will cause the open end of the container 154 to come into engagement with the face of the pattern 162. As the gasket on the frame 158 at the upper end of the container 154 engages the pattern '162, the springs 150 which surround the bolts 146 will compress and permit the container 154 to move relative to the arms 122. The initial setting of the container 154 is such that it would prevent further movement of the arms 122 toward the support 104; but the springs 150 yield and facilitate that movement. The springs 150 will act to maintain a predetermined pressure on the gasket 160 and thus will provide a positive bar to the leakage of admixed sand and binder through the joint between the gasket 160 and the pattern 162. The shaft 134 will continue to rotate :and the support 104 and the container 154 will rotate to the final position shown in Fig. 17. In moving from the position shown in Fig. 16 to the position shown in Fig. 17, the support 104 and the container 154 move substantially as a unit, and they preserve the tight seal between the gasket 160 and the pattern 162. As the support 104 and the container 154 reach the nal position of Fig. 17, lthe follower 196 in the switch housing 192 strikes the :actuator 216 and causes the limit switch 210 to halt the motor 190. A time delay switch, not shown, will then keep the motor 190 de-energized for a predetermined period to enable the heat from the pattern 162 to soften the binder. This period can be adjusted by appropriate ladjustment of the time delay switch, and the longer the time the thicker the shell mold that will be created. In one preferred embodiment of the invention, a time delay of seven seconds was found to provide shell molds of desirable thickness and strength. At the conclusion of the predetermined time cycle, a reverse switch will automatically close and the motor 190 will begin to rotate in the opposite direction. This will rotate the shafts 34 and 106 in the opposite direction and will rotate the shaft 185 in the opposite direction; thus rotating the support 104 and the container 154 in a counterclockwise direction and moving the follower 196 downwardly. Rotation of the shafts 34 and 106 will cause the patterncarrying support and the container 154 to pass through the stages of Figs. 16, 15 and 14 to the stage shown in Fig. 13. As the pattern-carrying support 104 and the container 154 move from the stage of Fig. 16 to the stage of Fig. l5, the container 154 will move away from the pattern 162, but at such time the loose sand and binder will have fallen to the bottom of the container 154 and none will be lost when the gasket 160 separates from the pattern 162. As the pattern-carrying support and the container 154 approach the initial position of Fig. 13, the follower 196 will strike the actuator 218 and cause the switch 214 to stop the motor. Thereafter, a second time delay switch will keep the motor de-energized so the binder in the shell mold can cure and harden. At the end of this second time cycle, a switch will close and energize the solenoid which controls the flow of uid to the cylinder 168; and thereupon the piston 170 will move upwardly and the ejecting pins 172 will raise the cured and hardened shell mold from the pattern 162. The operator will then grasp the ejected shell mold and place it in a suitable container. This completes the cycle of the molding machine, and thereupon the operator can again push the starting button and initiate a new cycle.

It is desirable to stop the motor 190 promptly when either of the limit switches 210 or 214 is actuated, and therefore the control circuit for the molding machine provided by the present invention will preferably plug that motor, as by introducing reversing current into it for a short time. Such an arrangement avoids variations in the length of the path of travel of the patterncarrying support 104 and the container 154 due to coasting of the motor. The reversing current will be discontinued when the time delay switch is actuated. In one preferred embodiment of the present invention, a complete cycle requires only forty five seconds, and a sturdy and rugged shell mold is thus provided every forty ve seconds.

The leads 178 from the pattern 162 will preferably be connected to the appropriate leads 96 by solderless connectors. Such an arrangement makes the replacement of the pattern 162 by a diiferent pattern a relatively simple matter. The solderless connectors will be suitably insulated to avoid short circuits.

In the molding machine shown in the drawing, the cornbined mass of the pattern-carrying support 104 and the elements thereon just about counterbalances the combined mass of container 154 and an average load of admixed sand and binder. In some instances, larger and deeper containers 154 will be desired; and in those instances the pattern-carrying support 104 should be provided with extensions that eXtend about the pattern 162 and receive the pivots 34 and 106. Such an arrangement will displace substantially the entire mass of the pattern-carrying support 104 to one side of the pivots 34 and 106, and the axis of those pivots will pass through container 154; and a part of the mass of that container and its contents will help the support 104 counterbalance the rest of that container and contents.

Whereas a preferred embodiment of the present invention has been shown and described in the drawing and accompanying description, it should be apparent to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof.

What we claim is:

1. A molding machine that can make shell molds and that comprises a frame, a pattern-carrying support, pivots that are supported by said frame and that rotatably secure said support to said frame, a container for molding sand, one end of said container being open, a pivot adjacent said open end of said container that connects said container and said pattern-carrying support together while permitting relative movement between said container and said pattern-carrying support, a track supported by said frame, a follower that is carried by said container and is supported and guided by said track, one end of said track being disposed at one side of said frame-supported pivots and the other end of said track being disposed at the opposite side of said frame-supported pivots, said patterncarrying support being rotatable about said frame-supported pivots from a normal position to an inverted position and then forward to said normal position and said container being movable along said track from a position adjacent the said one end of said track where the said open end of said container is up to a position adjacent the said other end of said track where the said open end of said container is down, said pattern-carrying support rotating into registry with said open end of said container intermediate said ends of said track where the said open end of said container is up, and a source of power to rotate said pattern-carrying support.

2. A molding machine as claimed in claim l wherein said track has an arcuate section adjacent said other end thereof and has a straight section extending to the said one end thereof.

3. A molding machine as claimed in claim l wherein said track has a portion that is a part of a circle which is concentric with said frame-supported pivots and wherein said track has a portion tangent to said circle, the rst said portion of said track being adjacent said other end of said track and the second said portion of said track being adjacent the said one end of said track.

4. A molding machine as claimed in claim l wherein said follower is adjacent the said open end of said container and wherein said follower and the pivot that connects said container and said pattern-carrying support are oppositely disposed of said container.

5. A machine that handles fluid material and that comprises a frame, a support rotatably mounted on said frame, a container for fluid material, one end of said container being open, a pivot that connects said container and said support together while permitting relative movement between said container and said support, a track supported by said frame, a follower that is carried by said container and is supported and guided by said track, said track having an arcuate portion and a portion tangent to said arcuate portion, said support being rotatable from a normal position to an inverted position and forward to said normal position and said container being movable along said track from-a normall position to an inverted position, said support rotating into registry with said open end of said container intermediate the ends of said track, and a source of power to rotate said pattern-carrying support.

6. A machine as claimed in claim 5 wherein said arcuate portion of said track is at one side of said support and wherein said tangential portion is at the opposite side of said support.

7. A machine as claimed in claim 5 wherein said arcuate portion of said track is part of the circumference of a circle that is concentric with said support and wherein said tangential portion of said track is straight.

8. A machine as claimed in claim 5 wherein said follower is a roller that rolls along said track and wherein said follower and said pivot are adjacent said open end of said container and wherein said follower and said pivot are oppositely disposed of said container.

9. A molding machine that can make shell molds and that comprises a frame, a pattern-carrying support, pivots that are supported by said frame and that rotatably secure said support to said frame, a container-carrying support, a container, a plurality of bolts that loosely maintain said container in assembled relation with said container-carrying support, a plurality of springs urging said container away from said container-carrying support, one end of said container being open, a pivot that connects said pattern-carrying support and said contailler-carrying support together while permitting relative movement between said supports, a track supported by said frame, a follower that is carried by said container-carrying support and is supported and guided by said track, said track having an arcuate portion and a second portion, said pattern-carrying support being rotatable from a normal position to an inverted position and then forward to said normal position and said container-carrying support being movable along said track from a normal position to an inverted position, said pattern-carrying support rotating into registry with said container intermediate the ends of said track, and a source of power to rotate said pattern-carrying support.

10. A molding machine that can make shell molds l and that comprises a frame, a pattern-carrying support, pivots that are supported by said frame and that rotatably secure said support to said frame, one of said pivots having an axially extending opening therein, a stationary support adjacent said one pivot, a flexible conductor of spiral configuration that has one end thereof connected to said stationary support, an insulator mounted on and rotatable with said one pivot, said flexible conductor having the other end thereof connected to said insulator, a lead that is connected to said other end of said flexible conductor and that extends through said opening in said one pivot, said lead extending to said pattern-carrying support, and a source of power to rotate said pattern-carrying support.

11. A molding machine that can make shell molds and that comprises a frame, a pattern-carrying support, pivots that are supported by said frame and that rotatably secure said support to said frame, one `of said pivots having an axially extending opening therein, a stationary sleeve of insulation adjacent said one pivot,

a'second sleeve of insulation 'that is' connected to and `rotateswith said one pivot, said second sleeve of insulation Vbeing disposed within and rotating relative to said stationary sleeve of insulation, a pluralityof ilexible conductors of spiral configuration disposed between said sleeves of insulation, the outer ends of said conductorsbcing secured to `said stationary sleeve of insulation in spaced apart relation and the inner ends of said conductors being secured to 'said second sleeve of insulation, a plurality of leads disposed in said second sleeve of insulation and in said axially extending opening in said one pivot' and being connected to the said inner ends of said conductors, and a source of power to rotate said pattern-carrying support.

l2. A molding machine as claimed in claim 11 wherein said conductors are spaced apart and isolated from each other by washers of insulation that extend between said sleeves of insulation.

13. A molding machine as claimed in claim 11 wherein said one pivot has a second axially extending opening therein and wherein a stationary sealing sleeve surrounds said one pivot, said second axially extending opening having a portion thereof which opens to the surface of said one pivot in register with said sealing sleeve and having a portion extending toward said pattern-carrying support, said sealing sleeve having three annular recesses at the inner face thereof, one of said recesses registering with the first said portion of said second axially extending opening, and the other two recesses being oppositely disposed of the first said recess and having O-rings therein, said one recess supplying uid under pressure to said second axially extending opening and said O-rings confining said uid while permitting rotation of said one pivot relative to said stationary sealing sleeve. A 14. A molding machine that can make shell molds and that comprises a frame, a pattern-carrying support, pivots that are supported by said frame and that rotatably secure said support to said frame, a container for molding sand, one end of said container being open, a link, between said pattern-carrying supportl and said container that interconnects said pattern-carrying support and said container while permitting relative movement of said pattern-carrying support and said container, a guide for said container that guides the movement of said container as said container is moved by said link during rotation of said pattern-carrying support, said pattern-carrying support being rotatable about said frame-supported pivots from a normal'position to an inverted position and then vforward to said normal position and said container being movable from a position with its open end up to a second position with its open end down, said pattern-carrying'support rotating into registry with said open end of said container before said container reaches said second position, and a source of power to rotate said pattern-carrying support.

References Cited in the file of this patent p UNITED STATES PATENTS 852,494

Germany Mar. 3,'1952 

